What is a common side effect of using sodium hydroxide in hair relaxers?

Using sodium hydroxide in hair relaxers commonly results in dryness of the hair. Sodium hydroxide is a strong alkaline chemical that works by breaking down the protein structure of the hair to relax curls and waves. While this process can straighten the hair, it also strips moisture from the hair shaft, leading to dryness and potential brittleness.

The other options reflect outcomes that are generally not associated with the use of sodium hydroxide in relaxers. Increased volume typically refers to a fuller, bouncier appearance, which may not occur after the straightening process. Enhanced shine is often a characteristic of well-moisturized hair, which might be compromised after using such a harsh chemical treatment. Lastly, softness is the desired quality after a treatment; however, sodium hydroxide can make the hair more coarse and less manageable if not properly followed by conditioning treatments. Thus, dryness stands out as the most common and significant side effect.